SFI SYSTEM ECM Power Source Circuit

DTC Code DTC Name
ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, the battery voltage is applied to the IGON terminal of the ECM. The input signal from the MREL terminal of the ECM causes a current to flow to the EFI MAIN relay coil, closing the EFI MAIN relay contacts and supplying power to terminal +B1, ACT1, ACT2, ACT3 and ACT4 of the ECM.

WIRING DIAGRAM

A330559E01

CAUTION / NOTICE / HINT

Note:

Inspection the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

  1. CHECK TERMINAL VOLTAGE (IGON TERMINAL VOLTAGE)

    1. Disconnect the ECM connector.

    2. Turn the ignition switch to ON.

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A35-19 (IGON) - Body ground

      Ignition switch ON

      11 to 14 V

    Result

    Result

    Proceed to

    OK

    A

    NG (w/ Entry and Start System)

    B

    NG (w/o Entry and Start System)

    C
    B

    CHECK HARNESS AND CONNECTOR (IG2 RELAY - ECM)Click here

    C

    CHECK HARNESS AND CONNECTOR (IGNITION SWITCH ASSEMBLY - ECM)Click here

    A

  2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI MAIN RELAY)

    1. Remove the EFI MAIN relay from the No. 1 engine room relay block.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      3 (EFI MAIN relay) - Body ground

      Always

      11 to 14 V

      2 (EFI MAIN relay) - Body ground

      Always

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI MAIN RELAY - BATTERY)

    OK

  3. INSPECT EFI MAIN RELAY

    1. Inspect the EFI MAIN relay.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE EFI MAIN RELAY

    OK

  4. CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY - ECM)

    1. Remove the EFI MAIN relay from the No. 1 engine room relay block.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      1 (EFI MAIN relay) - A35-28 (MREL)

      Always

      Below 1 Ω

      5 (EFI MAIN relay) - A35-5 (+B1)

      Always

      Below 1 Ω

      5 (EFI MAIN relay) - A35-1 (ACT1)

      Always

      Below 1 Ω

      5 (EFI MAIN relay) - A35-6 (ACT2)

      Always

      Below 1 Ω

      5 (EFI MAIN relay) - A35-18 (ACT3)

      Always

      Below 1 Ω

      5 (EFI MAIN relay) - A35-30 (ACT4)

      Always

      Below 1 Ω

      1 (EFI MAIN relay) or A35-28 (MREL) - Body ground and other terminals

      Always

      10 kΩ or higher

      5 (EFI MAIN relay) or A35-5 (+B1) - Body ground and other terminals

      Always

      10 kΩ or higher

      5 (EFI MAIN relay) or A35-1 (ACT1) - Body ground and other terminals

      Always

      10 kΩ or higher

      5 (EFI MAIN relay or A35-6 (ACT2) - Body ground and other terminals

      Always

      10 kΩ or higher

      5 (EFI MAIN relay) or A35-18 (ACT3) - Body ground and other terminals

      Always

      10 kΩ or higher

      5 (EFI MAIN relay) or A35-30 (ACT4) - Body ground and other terminals

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)

    1. Disconnect the ECM connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A35-53 (GND1) - Body ground

      Always

      Below 1 Ω

      A35-4 (GND2) - Body ground

      Always

      Below 1 Ω

      A35-3 (GND3) - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. CHECK HARNESS AND CONNECTOR (IG2 RELAY - ECM)

    1. Remove the IG2 relay from the center relay block.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      5 (IG2 relay) - A35-19 (IGON)

      Always

      Below 1 Ω

      5 (IG2 relay) or A35-19 (IGON) - Body ground and other terminals

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT IG2 RELAY

    1. Inspect the IG2 relay.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE IG2 RELAY

    OK

  8. CHECK TERMINAL VOLTAGE (POWER SOURCE OF IG2 RELAY)

    1. Remove the IG2 relay from the center relay block.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      3 (IG2 relay) - Body ground

      Always

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG2 RELAY - BATTERY)

    OK

  9. CHECK HARNESS AND CONNECTOR (IG2 RELAY - BODY GROUND)

    1. Remove the IG2 relay from the center relay block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      1 (IG2 relay) - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. CHECK HARNESS AND CONNECTOR (IG2 RELAY - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))

    1. Remove the IG2 relay from the center relay block.

    2. Disconnect the certification ECU (smart key ECU assembly) connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      2 (IG2 relay) - E49-20 (IG1D)

      Always

      Below 1 Ω

      2 (IG2 relay) or E49-20 (IG1D) - Body ground and other terminals

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    GO TO ENTRY AND START SYSTEM

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  11. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH ASSEMBLY - ECM)

    1. Disconnect the ignition switch assembly connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      E21-6 (IG2) - A35-19 (IGON)

      Always

      Below 1 Ω

      E21-6 (IG2) or A35-19 (IGON) - Body ground and other terminals

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. INSPECT IGNITION SWITCH ASSEMBLY

    1. Inspect the ignition switch assembly.

      Click here

    Result

    Proceed to

    OK

    NG
    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH ASSEMBLY - BATTERY)

    NG

    REPLACE IGNITION SWITCH ASSEMBLY

    Click here